This invention relates generally to electrical power distribution and, more particularly, to an electrical power distribution system for use in a hybrid fiber optic network.
Fiber optic communication networks are gaining in popularity due to the increased bandwidth that they provide and their proven reliability. Fiber optic networks can provide for voice, video and data communications. In this regard, fiber optic networks are being widely implemented to interconnect businesses, home offices, residences, schools, and the like. Further, the growing popularity of the internet is imposing increasing requirements for ultra high bandwidth for both downstream and upstream data communication. Therefore, fiber optic networks are needed to satisfy this ever-increasing demand for bandwidth.
Fiber optic networks typically utilize fiber optic cables that connect a head-end, such as a telephone company""s switching office, to a Universal Demarcation Point (xe2x80x9cUDPxe2x80x9d), such as a home or an office. The fiber optic cables include one or more glass fibers or strands placed in hollow buffer tubes. The number of optical glass fibers and buffer tubes in a fiber optic cable typically varies depending upon the particular implementation, the number of Universal Demarcation Points (xe2x80x9cUDPsxe2x80x9d) on the branch, the bandwidth requirement between the respective connection ends, and the like. Data or information is transported through the glass fibers as light pulses. Electronic equipment at each end of a fiber optic cable converts between electrical signals in an electrical conductor, such as a copper wire, and light pulses in the fiber optic cable.
In such fiber optic networks, electronic equipment and other customer premise equipment (xe2x80x9cCPExe2x80x9d) associated with the fiber optic network typically requires electrical power for operation. Usually, electrical power is supplied locally at each end of the optical network. The electrical power supplied at a head-end, such as a telephone company""s switching office, is usually reliable. At the CPE end of the optical network, commercial power may not be as reliable as the head-end. That commercial electrical power is delivered to the CPE via a plug-in type transformer plugged into the electrical outlet. The transformer converts the commercial electrical power from the outlet to the desired or appropriate voltage required by the CPE.
Commercial sources of electrical power at UDP locations, however, are not always dependable due to the voltage fluctuations and power outages inherent in commercial electrical power distribution. Further, such electrical power supply to the electronics equipment has a failure point in the plug-in type transformer which is susceptible to damage from voltage spikes, black outs, brown outs, and the like that often occur in commercial electrical power. Some transformer type power supplies have a rechargeable battery associated with them to provide an uninterrupted electrical power supply to the CPE during an electrical power outage. In most cases, the rechargeable battery only has an 8 hr. standby time and these rechargeable batteries have to be replaced from time to time due to their limited life span. These limitations limit their utility and dependability as backup sources of power, and add to the cost of maintaining the corresponding equipment. Thus, it is preferable to power CPE equipment from the head-end of the optical network. The head-end electrical power supply can be better regulated by equipment specially designed for that purpose. The head-end may also include back-up power generators that help provide even more reliable electrical power for a longer duration during an extended electrical power outage.
Accordingly, the objects of the present invention include overcoming one or more of the problems set forth above.
In one aspect of the invention, a fiber optic cable includes a pair of metal conductors in addition to the glass fibers or strands in the cable. The pair of metal conductors can carry electrical power from the head-end at a predetermined voltage. An electrical power distribution module is operatively connected to the pair of metal conductors at each splice case or optical branch that connects to a UDP or CPE or electronic equipment which requires electrical power for operation. The electrical power distribution module can be accommodated in a splice case or other apparatus associated with the fiber optic cable. The electrical power distribution module includes one or more power connectors for connecting CPE or other electronic equipment requiring electrical power. Each of the drop side connectors includes over-current protection, such as a fuse, in series with the equipment that is being supplied electrical power from the distribution module.